1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * X.25 Packet Layer release 002 4 * 5 * This is ALPHA test software. This code may break your machine, 6 * randomly fail to work with new releases, misbehave and/or generally 7 * screw up. It might even work. 8 * 9 * This code REQUIRES 2.1.15 or higher 10 * 11 * History 12 * X.25 001 Jonathan Naylor Started coding. 13 */ 14 15 #include <linux/if_arp.h> 16 #include <linux/init.h> 17 #include <linux/slab.h> 18 #include <net/x25.h> 19 20 LIST_HEAD(x25_route_list); 21 DEFINE_RWLOCK(x25_route_list_lock); 22 23 /* 24 * Add a new route. 25 */ 26 static int x25_add_route(struct x25_address *address, unsigned int sigdigits, 27 struct net_device *dev) 28 { 29 struct x25_route *rt; 30 struct list_head *entry; 31 int rc = -EINVAL; 32 33 write_lock_bh(&x25_route_list_lock); 34 35 list_for_each(entry, &x25_route_list) { 36 rt = list_entry(entry, struct x25_route, node); 37 38 if (!memcmp(&rt->address, address, sigdigits) && 39 rt->sigdigits == sigdigits) 40 goto out; 41 } 42 43 rt = kmalloc(sizeof(*rt), GFP_ATOMIC); 44 rc = -ENOMEM; 45 if (!rt) 46 goto out; 47 48 strcpy(rt->address.x25_addr, "000000000000000"); 49 memcpy(rt->address.x25_addr, address->x25_addr, sigdigits); 50 51 rt->sigdigits = sigdigits; 52 rt->dev = dev; 53 refcount_set(&rt->refcnt, 1); 54 55 list_add(&rt->node, &x25_route_list); 56 rc = 0; 57 out: 58 write_unlock_bh(&x25_route_list_lock); 59 return rc; 60 } 61 62 /** 63 * __x25_remove_route - remove route from x25_route_list 64 * @rt: route to remove 65 * 66 * Remove route from x25_route_list. If it was there. 67 * Caller must hold x25_route_list_lock. 68 */ 69 static void __x25_remove_route(struct x25_route *rt) 70 { 71 if (rt->node.next) { 72 list_del(&rt->node); 73 x25_route_put(rt); 74 } 75 } 76 77 static int x25_del_route(struct x25_address *address, unsigned int sigdigits, 78 struct net_device *dev) 79 { 80 struct x25_route *rt; 81 struct list_head *entry; 82 int rc = -EINVAL; 83 84 write_lock_bh(&x25_route_list_lock); 85 86 list_for_each(entry, &x25_route_list) { 87 rt = list_entry(entry, struct x25_route, node); 88 89 if (!memcmp(&rt->address, address, sigdigits) && 90 rt->sigdigits == sigdigits && rt->dev == dev) { 91 __x25_remove_route(rt); 92 rc = 0; 93 break; 94 } 95 } 96 97 write_unlock_bh(&x25_route_list_lock); 98 return rc; 99 } 100 101 /* 102 * A device has been removed, remove its routes. 103 */ 104 void x25_route_device_down(struct net_device *dev) 105 { 106 struct x25_route *rt; 107 struct list_head *entry, *tmp; 108 109 write_lock_bh(&x25_route_list_lock); 110 111 list_for_each_safe(entry, tmp, &x25_route_list) { 112 rt = list_entry(entry, struct x25_route, node); 113 114 if (rt->dev == dev) 115 __x25_remove_route(rt); 116 } 117 write_unlock_bh(&x25_route_list_lock); 118 119 /* Remove any related forwarding */ 120 x25_clear_forward_by_dev(dev); 121 } 122 123 /* 124 * Check that the device given is a valid X.25 interface that is "up". 125 */ 126 struct net_device *x25_dev_get(char *devname) 127 { 128 struct net_device *dev = dev_get_by_name(&init_net, devname); 129 130 if (dev && 131 (!(dev->flags & IFF_UP) || (dev->type != ARPHRD_X25 132 #if IS_ENABLED(CONFIG_LLC) 133 && dev->type != ARPHRD_ETHER 134 #endif 135 ))){ 136 dev_put(dev); 137 dev = NULL; 138 } 139 140 return dev; 141 } 142 143 /** 144 * x25_get_route - Find a route given an X.25 address. 145 * @addr: - address to find a route for 146 * 147 * Find a route given an X.25 address. 148 */ 149 struct x25_route *x25_get_route(struct x25_address *addr) 150 { 151 struct x25_route *rt, *use = NULL; 152 struct list_head *entry; 153 154 read_lock_bh(&x25_route_list_lock); 155 156 list_for_each(entry, &x25_route_list) { 157 rt = list_entry(entry, struct x25_route, node); 158 159 if (!memcmp(&rt->address, addr, rt->sigdigits)) { 160 if (!use) 161 use = rt; 162 else if (rt->sigdigits > use->sigdigits) 163 use = rt; 164 } 165 } 166 167 if (use) 168 x25_route_hold(use); 169 170 read_unlock_bh(&x25_route_list_lock); 171 return use; 172 } 173 174 /* 175 * Handle the ioctls that control the routing functions. 176 */ 177 int x25_route_ioctl(unsigned int cmd, void __user *arg) 178 { 179 struct x25_route_struct rt; 180 struct net_device *dev; 181 int rc = -EINVAL; 182 183 if (cmd != SIOCADDRT && cmd != SIOCDELRT) 184 goto out; 185 186 rc = -EFAULT; 187 if (copy_from_user(&rt, arg, sizeof(rt))) 188 goto out; 189 190 rc = -EINVAL; 191 if (rt.sigdigits > 15) 192 goto out; 193 194 dev = x25_dev_get(rt.device); 195 if (!dev) 196 goto out; 197 198 if (cmd == SIOCADDRT) 199 rc = x25_add_route(&rt.address, rt.sigdigits, dev); 200 else 201 rc = x25_del_route(&rt.address, rt.sigdigits, dev); 202 dev_put(dev); 203 out: 204 return rc; 205 } 206 207 /* 208 * Release all memory associated with X.25 routing structures. 209 */ 210 void __exit x25_route_free(void) 211 { 212 struct x25_route *rt; 213 struct list_head *entry, *tmp; 214 215 write_lock_bh(&x25_route_list_lock); 216 list_for_each_safe(entry, tmp, &x25_route_list) { 217 rt = list_entry(entry, struct x25_route, node); 218 __x25_remove_route(rt); 219 } 220 write_unlock_bh(&x25_route_list_lock); 221 } 222